1. Field of the Invention
The present invention generally relates to a handheld computer or personal digital assistant (PDA) and more particularly to the electrical interface between the PDA and an option pack.
2. Description of the Related Art
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Handheld computers or personal digital assistants (PDAs) are becoming increasingly useful in today""s computer industry. Conventional PDA units typically provide a user with a handheld device which serves as an abbreviated version of a larger laptop and desktop computer system. They provide a user with an operating system and various software programs to accommodate scheduling, word processing, and a variety of other functions. Advantageously, these units comprise small, light-weight systems which provide a significant amount of computing power. However, it is clear that with the advantages of decreasing the size of a computing system, certain functional tradeoffs typically must be made. For extended computer use, complex computing tasks, and memory intensive applications, laptops and desktops are still virtually essential. Because laptops and desktops are larger, they have more memory and processing capabilities. Deciding what applications and functions to omit to sufficiently decrease the size of the computer unit offers a significant challenge.
To meet this challenge, PDAs are often equipped with streamlined base functions. Certain units may be off-the-shelf units with certain standard applications. Other units may be custom units which are designed in accordance with customer specifications. Still other units may provide for the downloading of software by a user, while other unit""s may provide docking interfaces which allow portable option packs to be neatly coupled to the PDA to provide additional capabilities. The electrical interface, identification scheme, software exchange, and interface configuration between the option pack and the PDA provides a difficult challenge for designers.
The present invention may address one or more of the problems set forth above.
Certain aspects commensurate in scope with the disclosed embodiments are set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms the invention might take and that these aspects are not intended to limit the scope of the invention. Indeed, the invention may encompass a variety of aspects that may not be set forth below.
In accordance with one embodiment of the present invention, there is provided an option pack interface comprising: a Serial Peripheral Interface; a connector configured to transmit and receive a plurality of signals to and from a main unit of a personal digital assistant and further configured to transmit and receive the plurality of signals through the Serial Peripheral Interface; and a memory device electrically coupled to the connector through the Serial Peripheral Interface and configured to store identification information correlative to an option pack.
In accordance with another aspect of the present invention, there is provided a personal digital assistant comprising a main unit and an option pack. The main unit comprises a processor; a controller operatively coupled to the processor through a first data bus; and a first connector operatively coupled to the controller through a second data bus and configured to receive a second connector on an option pack. The option pack comprises: a Serial Peripheral Interface; a second connector configured to transmit and receive a plurality of signals to and from the first connector in the main unit and further configured to transmit and receive the plurality of signals through the Serial Peripheral Interface; and a memory device electrically coupled to the connector through the Serial Peripheral Interface and configured to store identification information corresponding to an option pack.
In accordance with a further embodiment of the present invention, there is provided an option pack comprising an interface configured to support: one or more personal computer memory card international association/compact flash (PCMCIA/CF) devices; static memory access; input/output device access; one or more Serial Peripheral Interface (SPI) data buses; and a memory device configured to store identification information.
In accordance with still another embodiment of the present invention, there is provided an option pack comprising: a first battery; and an interface configured to provide a means for simultaneously charging the first battery on the option pack and a second battery on a main unit of a personal digital assistant.
In accordance with an alternate embodiment of the present invention, there is provided a personal digital assistant comprising a main unit comprising: a processor; a memory device operatively coupled to the processor and configured to temporarily store software applications and associated drivers; a controller operatively coupled to the memory device, the controller configured to download the software and associated drivers from an option pack; and a connector operatively coupled to the controller and configured to transmit identification information from the option pack to the controller and further configured to transmit the software and associated drivers from the option pack to the memory device.